Olivine (Mg,Fe)
2
SiO
4
Fluorite CaF
2
Every
manufactured
product contains
materials
derived from
minerals
Most people are
familiar with
basic metals:
Al in beverage can
Cu in electrical wires
Au in Jewelry
Si in computer chips
Realgar
Beryl (aquamarine)
Pencils = graphite (C)
Baby powder Talc
Mg
3
(Si
2
O
5
)(OH)
4
Quartz is a major
ingredient of
ordinary glass
(Na,Ca)(Fe,Mg,Al,Li)
3
Al
6
(BO
3
)
3
Si
6
O
18
(OH)
4
Tourmaline
Rock: solid
mass of
mineral or
mineral like
matter that
occurs
naturally as
part of the
Earth
Crust Whole Earth
Oxygen 46.3 % 29.5%
Silicon 28.2% 15.2%
Aluminum 8.2% 1.1%
Iron 5.6% 34.6%
Calcium 4.1% 1.1%
Sodium 2.4% 0.6%
Potassium 2.1% 0.1%
Magnesium 2.3% 12.7%
Titanium 0.5% 0.1%
Nickel trace 2.4%
All others trace 2.7%
Abundance of the elements (wt. %)
Any naturally occurring inorganic solid that posses an
orderly crystalline structure and a definite chemical
composition.
Geologists define a Mineral as:
May Be Elements or Compounds
• Native Minerals
– Form uncombined in
nature
– Au, Ag, Cu, S, C
–
Gold, silver, copper,
sulfur, diamond
• Most are compounds
– Form from magma
– Form as evaporites
– Changed by heat,
pressure, or water
Silicates
• 90% minerals on Earth
–
Most common
• Si, O, and 1 or more
metallic ions
• SiO4
• Tetrahedron shape
Identifying Minerals
• Over 200 known
• Can be identified from
physical properties
How can I
tell what
this is?
Identification Properties
• COLOR
– Least useful
– Many have similar
colors
– Other elements may
change color
– Beryl (emerald)
Identification Properties
• LUSTER
• The shine in
reflected light
LUSTER TERM DESCRIPTION
adamantine very brilliant - as in diamond
resinous
looks like resin or hardened
tree sap
vitreous
glassy, but not as shiny as
diamond
metallic looks like metal
silky has a smooth and fibrous sheen
pearly smooth and iridescent
greasy looks like it's coated with oil
earthy looks like dirt
LUSTER
• Glassy
• Adamantine
• Greasy
